<nav class="navbar navbar-default">
	    <div class="container-fluid">
	    <div class="navbar-header">
	      <a class="navbar-brand" href="#">我的博客后台</a>
	    </div>
	    <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
	      <ul class="nav navbar-nav">
	        <li class="<?php if($pagename==1){echo "active";} ?>"><a href="<?php echo site_url('admin/article/index'); ?>">文章列表 </a></li>
	        <li class="<?php if($pagename==2){echo "active";} ?>"><a href="<?php echo site_url('admin/catalog/index'); ?>">分类列表</a></li>
	      </ul>
	      <ul class="nav navbar-nav navbar-right">
	        <li class="dropdown">
	          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">
	          <?php echo $_SESSION['username'];?><span class="caret"></span></a>
	          <ul class="dropdown-menu">
	            <li><a href="<?php echo site_url('/admin/auth/out_login');?>">退出</a></li>
	          </ul>
	        </li>
	      </ul>
	    </div>
	  </div>
	</nav>